Authorities have said as many as 15 people are feared dead and more than 160 others were injured in the explosion that leveled homes and businesses in the farming community of West, Texas.

Perry emphasized during a Thursday morning news conference that much of the information about victims remains "very preliminary." He says President Barack Obama has offered a quick turnaround of declaring McLennan County an emergency disaster that is eligible for federal aid.

Perry says at least 75 homes were damaged in the blast. Lt. Gov. David Dewhurst says the explosion Wednesday night knocked people "all over the town" back 10 feet, including some through windows.

Witnesses describe impact of fertilizer plant explosion

Mushroom caused by explosion of fertilizer plant in Texas (Facebook)

Witnesses are describing the impact of the explosion at a fertilizer plant near Waco, Texas that left as many as 15 people dead and more than 160 others injured.

Erick Perez was playing basketball at a nearby middle school yesterday evening when a fire started at the plant. He says he and his friends thought nothing of it, but then the smoke changed color. He says the blast threw him, his nephew and others to the ground, and showered the area with hot embers and debris.

Julie Zahirniako had been with her son at the school playground. She says the explosion threw her son four feet in the air, breaking his ribs.

She says she saw people running from a nearby nursing home, and that the roof of the school lifted into the sky.

The nursing home was also badly damaged. One man who arrived there before the first responders says he and his wife found residents in wheelchairs trapped in their rooms, amid dark hallways and ceilings that had collapsed.